Electric lamp



3 1939- H. D BLAKE 2,158,849

ELECTRIC LAMP Filed Janf 24, 1935 2 Sheets-Sheet 1 Inventor:

Harold D. Blake,

is Attorne y.

May 16, 1939.

H. D. BLAKE 2,158,849

ELECTRIC LAMP 2 Sheet-Sheet 2 Filed Jan. 24, 1935 I nventor': Harold D.Blake,

' Z-[is Attorne y.

Patented May 16, 1939 PATENT OFFICE ELECTRIC LAMP I darold D. Blake,Cleveland Heights, ON, I-

signor to General Electric Company, a comration of New York ApplicationJulian 24, 1935, Serial No. 3,334

7 Claims. (Cl. 178-32) My invention relates to electric lamps andsimilar devices and to holders for mounting said lamps or similardevices and conducting current to the electric energy translationelement or filament thereof.

One of the objects of my invention is to provide an electric lamp orsimilar device having a base of novel and simple design together with aquickly detachable holder for engaging said base and conducting currentthereto.

My invention may be applied to electric lamps comprising an envelope orbulb having a base at one end or to lamps of the double-ended tubulartype comprising a tubular bulb having a base at each end thereof such,for example, as the type disclosed in U. S. patent application SerialNo. 687,011, Paul O. Cartun, filed April 20, 1933, Patent No. 2,032,791.

In the type of lamp disclosed in the Cartun patent application referredto, the filament extends practically the whole length of the lamp andthe tubular bulb extends unshaded substantially to the extreme ends ofthe lamp so that, withsuitable holders or mounting devices, a series oflamps may be mounted end to end practically without interveningstructures that would interrupt the line of light. However, considerabledifficulty has been experienced in the design of a satisfactory holderfor this type of lamp. This difiiculty is obviated when the ends orbases of the lamp are constructed according to my invention and securedto holders also constructed in accordance with my invention. The saidholders occupy a minimum amount of space between the ends of adjacentlamps and afford a good, safe 'and simple means of support andelectricai'connection.

Further features and advantages of my invention will appear from thefollowing description of species thereof and fromthe drawings.

In the drawings, Fig. 1 is a perspective view of an incandescent lampcomprising my invention; Fig. 2 is a vertical section on an enlargedscale of a portion of the lamp and a socket shown in plan view in Fig.3, the section being taken on the line 2-1 of Fig. 3;'Fig. 4 is avertical section through an adapter which permits mounting the lamp in astandard screw-threaded socket, and Fig. 5 is a plan view thereof; Fig.6 is a longitudinal section of a double-ended tubular lamp comprising myinvention; Fig. (is an enlarged perspective and partial section of aholder and lamp respectively; Fig. 8 is an elevation, partly in section,of a series of lamps and holders of the type shown in Figs. 6 and 7mounted in sockets; Fig. 9 is a front eletaining about twenty-nine percent of vation of one of the holders 9. socket which is shown insection; Fig. 10 is a partially diagrammatic view of a series of socketsshowing the electrical connections thereto; Figs. 11 and 12 are frontand side elevations respec- 5 tively of a modified holder; Figs. 13 and14 are a front and side view in section respectively of another modifiedholder; and Fig. 15 is a perspective view of still another modifiedholder.

Referring to Fig. 1, the lamp bulb or envelope lli containing a filamentII which has its ends secured to the inner ends of lead wires I 2, l3and is supported at intermediate points by the ends of support wires II.The opposite ends of said support wires I4 and portions 15 of the leadwires i2, i3 are sealed in a glass A metal disc l6 (Fig. 2) is sealed tothe edges of the opening at the end of the bulb It to constitute an endwall and contact. The said disc is preferably of the general typedisclosed in the Cartun application hereinbefore referred to, andconsists of a metal or alloy which has a. coefficient of expansionapproximating that of the glass of which the bulb is made and sealsreadily thereto by fusion. For a soft glass bulb the disc is preferablymade of an iron alloy conchromium, such as an alloy marketed bytheAllegheny Steel Company as Allegheny 55. The disc I6 is preferablyconcave or dish-shaped so that it may be made of thin material and stillbe adequately strong.

The disc i 6 has a round cavity or depression l1 at the center,preferably of an inverted conoidal form, that is, it preferablyincreases in diameter inward from the edge or surface of the disc, themaximum diameter of the particular design shown in Fig. 2 being at thepoint l8. In other words, the sides of the said cavity diverge inwardlyfrom its edge. described as a centrally located subspherical cavity witha constricted orifice. The end of the lead wire i2 is formed into a loopI9 is a plane at right angles to the axis of the lamp, the said loopportion I 9 encircling the shoulder'or boss formed by the depression II.The lead wire I3 extends through an exhaust opening 20 at the center ofthe cavity II, the said opening being sealed by a mass of glass 2| whichalso insulates the said lead wire l3 from the disc IS. The mass of glass2| is formed by fusing down a portion of a glass exhaust tube which waspreviously fused to the disc it around the opening 20 and through whichthe bulb II was exhausted. The

of Fig. 8 mounted in lead wire l3 may be exposed at the surface 01'comprises a glass 10 The cavity may also be 40 thegiassmassIltoserveinitseliasthecenter contactil'iorthe lamp,thedisc ilservingaa theother contact.

I'iga2and2showoneiormoiholderorsocket thatmaybe usedior mounting thelamp. The said socket comprises a body portion 22 oi insulatingmaterial. One oi the contacts consists oi a metal disc 22 located withinthe socket and secured to a terminal 22 by screws 22. The center portionoi said disc 22 is iormed into a plurality (iour) oi upwardly extendingresilient fingers or prongs 22 which are radially compressible. The saidprongs 22 are annularly disposed and extend outwardly and then inwardlyso that when the lamp is inserted in the socket, the said prongs 22 arefirst compressed by the outer edge oi the walls oi the cavity H in thedisc l2 and then snap outward into the enlarged portion of the saidwalls oi said cavity, similar to a glove iastener. The socket alsocomprises a center contact consisting of a resilient metal strip 21disposed in a hole 22 at the center oi the socket and connected to aterminal 22 by a screw 22. The terminal 22 is electrically connected tothe disc l2 and lead wire i2 through the disc 22 and prongs 22, whilethe terminal 22 is electrically connected to the lead wire i2, whichitseli in this case constitutes the center contact oi the lamp, throughthe center contact strip 21 oi the socket.

Figs. 4 and 5. illustrate a screw-threaded adapter or holder which maybe mounted in the conventional type oi screw-threaded sockets to permitmounting the lamp therein without replacing the sockets in existinginstallations. The

said adapter comprises a cylindrical body portion 2| oi insulatingmaterial having an annular cap '22 secured to its upper end by screwthreads 22. A metal contact disc 22 and an insulating disc 22 are lockedbetween a shoulder in the said cap 22 and the body portion 2|. The saidmetal disc 22 has an upstanding annular and concave lamp engagementportion 22 at the center, the said engagement portion and the major partoi the disc being divided into a plurality (five) oi segments by radialslots 21. Holes 22 are punched inthedisc22 betweenthe saidslots21toaddto the resiliency oi the segmental engagement portion. A metalcontact strip 22 extends through a longitudinal slot or channel 22 inthe body portion 2|. The upper end tends laterally between the discs 22and 22,.being in electrical contact with said disc 22. The lower end ofsaid strip 22 extends through a slot in a cup-shaped shell 2| mounted onthe lower end oi the b p rtion 2| and laterally between thebottomoisaidshell 2| andaninsulatingdisc 22. The shell 2i is therebyelectrically connected to the disc 22 by the'strip 22. The said shell isprovided with screw threads 22 for t with the screw-threaded shell oi aconventional socket. Another contact strip 22 extends through alongitudinal slot 22 in the body portion 2|.'I'heupperendportion22oisaidstrip22isbent toward the center oi the saidbodyportion 2| anditbearsagainstthebottomoitheinsulatmg in thebottomoishell 2| and the disc iaterallybetweentbebottomoisaiddisc 2ametalendcontactcap. Thesaidsecuredtotheendoiathreadedpin22whichextendsthroughcentralaperturesintheloweroi contact strip 22, disc 22, and bottom oi oi said strip 22 ex 2|andintoacentralroundholellinthebody portion 2| in which it is securelyheld.

WhenthelampoiFig. lisinsertedinthe adapter. the segments oi theengagement portion 22 snap into the cavity H in the disc l2 and the endcontact 2| on the lamp extends through the aperture 21 and engages theupper portion 22 oi the strip 22 which constitutes the center contact oithe adapter. The said lamp base disc I2 is thus electrically connectedto the screw-threaded shell 2| and the center contact 2| to the endcontact 22 oi the adapter.

The particular iorm oi lamp base engagement portion 22 shown in Figs. 4and 5 appears to be the most satisfactory oi the various iorms shown inthe drawings.

Fig. 6 illustrates a double-ended tubular incandescent lamp oi the typedisclosed in the hereinbeiore-mentioned Cartun patent application. Itcomprises a tubular glass bulb or envelope 2| having metallic discs 22,22, one sealed to each end thereoi as an end wall and contact. The discs22, 22 are of the same type as the disc i2 in Figs. 1 and 2 except thatthe disc 22 is not provided with an exhaust aperture. The bulb isexhausted through an aperture 22 at the center 01! the disc 22, the saidaperture being sealed by a mass oi glass 22 which constitutes theresidue oi an exhaust tube and is sheltered in the cavity or depression22 at the center 01 the disc. The said cavity 22 and the cavity 21 indisc 22 are oi the same design as the cavity l1 in disc i2 (Figs. 1 and2). The filament 22 extends substantially the entire length oi the bulb2| and is electrically connected at each end to one of the discs 22, 22.The filament supporting structure may consist oi a (glass) stay rod 22,having terminal wires 22 and 2| iused to respective ends thereoi, shortsupport wires 22, 22 welded to the wires 22, 2| respectively and securedone to each end oi the filament, and support wires 22 spaced along thestay rod 22 and iused thereto and supporting the said filament atintermediate points. The end portions of the wires 22, 2| are iormedinto loops which engage the shoulders or bosses iormed by the cavities21, 22.

The lamp is mounted on holders or mounting devices 22 (Figs. 7 to 9),the lamp-engaging portions oi which consist of resilient fingers orprongs 22 (similar to the prongs 22 in Figs. 2 and 3) which snap intothe cavities 22, 21 in the discs 22 and 22, thereby drawing the saidholders against the said discs and making a good electrical connectiontherewith. The said holders 22 are iormed from sheet metal strips 21 andpreierably have some iorm oi socket-engaging portion 22. The saidsocket-engaging portion 22 is icrmed by folding back the end portion ofthe strip 21 at right angles to the main portion thereof. The iorwardedge oi this iolded portion is then split at 22 and iormed at'that pointinto a cylindrical protuberance 12 which engages with a contact strip 1|in a socket 12. The entire holder". with the exception oi thesocket-engaging portion or prong 22 and the lamp-engaging prongs 22, ispreierably covered or coated with an insulating material 12 which may be-sprayedormoldedthereonormaybeinthe iorm oi a cap secured thereto. Theholder 22 is shown in Hg. '1 before the application oi the insuiatingmaterial. lugs 12 being preierably provided to more securely hold theinsulation thereon.

As shown in Figs. 2 and 10, when a number oi lamps 2| are arranged endtoend, the sockets 12 the line.

By forming the terminal prong portion 88 of the holder 65 so that it isin a plane at right angles to the plane of the body portion 61 and lampengagement prongs 66, it lies substantially in the plane through thelongitudinal axis of the lamp or parallel thereto so that the terminalstrips II or the sockets may be made a little wider than the distancebetween the opposite edges of the adjacent terminal prongs 68, therebyleaving some room for small variations in the lengths of the lamps Thesaid lamps 5| may be mounted by first attaching the holders 65 to theends thereof and then grasping the bulb 5| and moving the lamp laterallytoward the sockets 12 to insert the prongs 68 therein.

Figs. 11 and 12 illustrate a holder having lampengagement fingers orprongs I5 similar to the prongs 66 oi! the holder 65, but the socket-emgagement portion or prong 16 has turned-up edges 11. The said edges 11may constitute the socket terminal engagement portions so that thisholder 1 is also adjustable in the socket longitudinally of terminal ofa socket.

the lamp axis in the same manner as the holder 85 of Figs. 8 to 10. Thesaid edges 11 may be provided with protuberances 11' or indentations forengagement with coacting indentations or protuberances in the socketterminals. The rim 19 of the body portion 88 of the holder may also beturned up to form a securing or anchoring means for an insulating cap orcoating (not shown).

Figs. 13 and 14 illustrate another modified holder in which the lampbase engagement prongs or segments 8| are similar to the prongs 66 ofthe holder 65 in Figs. 8 to except that there is but little spacebetween the adjacent edges thereof. A holder with prongs of this typecould not be used withthe disc 53 in Fig. 6 because of the presence ofthe glass mass 55 unless the cavity 56 were made sufliciently deep.However, -it could also be used on either end'of the lamp if the saidglass mass were eliminated from the outside of the disc and the lampexhausted in some other manner, for example through the side wall of thebulb 5|. The socket-engaging prong portion 82 of the holder may beprovided with a protuberance 83 for engagement with the The circularbody portion 84. of the holder is encased in an insulating cap 85 whichmay be made of a molded composition and has a projecting rim or edgeportion 86 which surrounds the end of the lamp 5| and completelyencloses the disc 52, thereby preventing accidental contact therewith.

Fig. illustrates still another modified holder in which the lamp baseengagement portion consists of a resilient split ring 81 extendingoutward from the body portion 88 and preferably increasing in diametertoward its outer edge so that it will snap into the cavity 56, or 51 ofthe discs 58, 52. The socket-engaging portion consists of a prong 88extending from the body portion 88 and may have a hole 88 therein forengagement with a protuberance on a socket terminal member.

Obviously, the insulating cap 85 in Figs. 13

3 and 14' may be used with the holders in Figs.

11, 12 and 15 and a somewhat similar cap may be used with the holder 65in Fig. '7. Also, the- 1. An electric lamp. comprising a tubular glassenvelope having a metal disc sealed directly to the edges of the openingat each end thereof, each of said discs having a round cavity thereinfor engagement with a holder, said cavity forming a boss at the insideof thedisc, a filament extending longitudinally through the envelopefrom end to end thereof and electrically connected at each end to one ofsaid discs, and a support structure for said filament comprising a staymember extending longitudinally through said envelope and having wireend portions looped around the said bosses on said discs, and supportwires spaced along and extending from said stay member and engaging saidfilament.

2. The combination of an electric lamp comprising a glass envelopehaving a flattened end wall comprising a metal disc sealed to andforming a part of said envelope, said disc having a cavity therein witha constricted orifice and adapted for engagement with radiallycompressible spring fingers of aholder.

3. The combination of an electric lamp comprising a glass envelopehaving a flattened end 'wall comprising a metal disc sealed to andforming a part of said envelope, said disc forming a contact and havinga cavity therein with a constricted orifice and adapted for engagementwith radially compressible spring fingers of a holder.

4. The combination of an electric lamp comprising a tubular glassenvelope having a fiattened end wall at each endthereof comprising ametal disc sealed to and forming a part of said envelope, each of saiddiscs forming a contact and having a cavity therein with a constrictedorifice and adapted for engagement with radially compressible springfingers of a holder.

5. The combination of an electric lamp comprising a glass envelopehaving a flattened end wall comprising a metal disc sealed to andforming a part of said envelope, said disc having a cavity therein witha constricted orifice and constituting a contact for said lamp, a secondcontact member extending through a seal in the center of said disc andinsulated therefrom, a holder comprising a sheet metal member havingannularly disposed radially compressible spring fingers extendingoutward from a face thereof, said fingers being compressed by saidorifice of said disc cavity upon insertion therein and then snappingoutward within said cavity to draw said sheet metal member and disctogether, a contact disposed at the center of said spring fingers andinsulated therefrom and engaging the said second contact extendingthrough said disc.

6. The combination of an electric lamp com prising a glass envelopehaving a flattened end wall comprising a metal disc sealed to andforming a part of said envelope, said disc having a cavity therein witha constricted orifice, and a holder comprising a sheet metal memberhaving annularly disposed radially compressible spring fingers extendingoutwardly from the face thereof, said ringers being compressed by saidoriiice of said disc cavity upon insertion therein and then snappinsoutward within said cavity to draw said sheet metal member and said disctogether.

7. The combination of an eiectriclamp comprising a tubular glassenvelope having a flattened end wall at each end thereof comprising ametal disc sealed to and forming a part of said envelope, each of saiddiscs having a cavity therein with a constricted orifice, and a holdercomprising a sheet metal member adapted to copperate with each end 0!said tubular glass envelope, each or said sheet metal members havingannularly disposed radially compressible spring nngers extending outwardfrom the face thereof, said fingers being compressed by the constrictedorifice oi the cooperating disc cavity upon insertion therein and thensnapping outward within said cavity to draw said sheet metal member anddisc toiether.

HAROLD D. BLAKE.

